Apple has released iPhoto ’11 9.2.3, which fixes an issue where iPhoto could crash when running on a Mac system with multiple user accounts. Aside from that, the update offers only the standard trope of “improves overall stability.” ($14.99 new from the Mac App Store, free update through Software Update or the Mac App Store, 256.9 MB via Software Update or 354.55 MB via Apple’s support page)
Thoughtful, detailed coverage of the Mac, iPhone, and iPad, plus the best-selling Take Control ebooks.
Use Shift to Compare Edits in iPhoto '08
In iPhoto '08, while you're editing a photo, press the Shift key to see a "before" view; let it up to see the "after" view. It's much faster and easier than using Undo and Redo.